Chosen Solution
I have only one charger, the one it came with. Everything was fine until today. I can’t charge from usb or even have the pc see the iPhone. Charging from wall or car charger works fine. Also won’t work on co-workers cable. Co-worker’s iPhone works fine on my cable. iPhone was purchased 29 days ago.
It sounds like a cable or connector aproblem. Try replacing the cable and see if that fixes it. If you continue to have problems that generally means the connector in the phone is bad. You will need to replace it in order to get full functionality back. The guide to replace the connector can be found here: iPhone 3GS Dock Connector Replacement
if the iPhone is not detected after connecting to the computer, it could also be a problem with the usb port, sometimes the voltage is way to low or one of the data pins is bent. try to connect the iPhone to a different usb port/computer
